Half to john forrest



J. MGGAFFREY.

SAFETY WATER GAGE.

(No Model.)

No.` 349,509. vPatented Sept. 2 1, 1886.

' f Hafen/E011 James McCaffrey 'by his 11215601? `y-s- WLn/eases i N.PETERS, PnomLiumgmpher. washmxon. u. c

l UNITED STATES PATENT OEEICEo JAMES MCCAFFBEY, OF PHILADELPHIA,PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO JOHN FORREST, OF SAME PLACE.

SAFETY WATER-GAGE.

SPECIFICATION forming part of Letters Patent No. 349,509, datedSeptember 21, 1886. Application filed February 15, 1836. Serial No.191,985. No model.)

.To all whoml it may concern:

Be it known that I, JAMES MCCAEEREY, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented certainImprovements in Safety Water-Gages, of which the following is aspecification.

My invention relates to that class of safety water-gages which areprovided with 'valves to close and prevent the escape of water or steamin the event of the breaking of the glass tube of the gage, the objectsof my invention being to simplify the construction of a watergage ofthis class, to present as little obstruction as possible to the iiow ofwater or steam into or from the gage-tube, to prevent the accumulationof dirt on the valves or lvalve-seats, and to insure the proper closingof the safety-valves when the glass tube of the gage is broken.

In the accompanying drawings, Figure l is a side view, partly insection, of a safety water-gage,showing my improvements; Fig. 2, avertical section of the duplex safety-valve for the gage; Fig. 3, a sideview of part of the same; and Fig. 4, a sectional plan view of saidvalve .on the line 1 2, Fig. 2.

` A represents part of the shell of a steamboiler, provided withvalve-casings B B, between which is confined the glass tube D of thegage, said tube being protected by guardrods a, attached to plates b onthe casings of the valves in the usual manner. The glass tube D isseated at cach end against a packing-strip,d, carried by a tubularvalve, F, which is adapted to a seat in the outer end of a tube, G,'screwed into a gland, f, or other part of the valve-casing B, so as tobe adjustable therein, the tube being retained in this posi` tion afteradjustment by means of a lock-nut, g. The inner end of the tube G formsa seat for a valve, H, connected to the valve F by a twisted stem, i,which, preferably, is integral with the said valve F, the valve I-Ihaving an internally-threaded opening for the reception of the threadedend of the stem, as shown in Fig. 2. f

In applying the gage the glass tube D is inserted between the upper andlower valves, F F, and the tubel G then adjusted until said valves aretightly seated in the ends of the tubes and the packing d pressed firmlyagainst the ends of the tube D. The length of the stem 'i is such thatthe valves II are thereby held away from their seats, so as to permit afree passage of water or steam into o1' from the glass tube of the gagethrough the tube G and hollow valves F. If the glass tube D is broken,however, the support is removed from the valves F, and the valves H areat once forced to their seats, so as to prevent the escape of eithersteam or water through the tubes G.

By using a single stem, t', instead of a stem having three or more ribs,as usual, for connecting thevalves F and H, I reduce the area of thepassage through the tube G as little as possible, and by twisting saidstem Iimpart a whirling motion to the steam or water passing throughsaid tube, this having a tendency to keep the valves II and the seats atthe ino ner ends of the tubes clean, and thus insure the proper closingof the tubes by said valves II when the glass tube D is broken.

By making the stem 'i integral with the valve F and securing the valveI-I to said stem, opportunity is afforded for the formation of a centralopening, m, of large area in the valve F, whereas if the reverseconstruction is adopted and the stem i screwed into said valve F theformation of such an opening is prevented.

I claim as my inventionl. The combination of the glass tube D and casingB of a water-gage with the tube G, having end valve-seats, the tubularvalve F, bearing upon the end of the glass tube and adapted to the outerseat of the tube G, and the valve H, connected to said valve F, andadapted to the inner seat of said tube G, all substantially asspecified.

2. The combination of the glass tube D and casing B of the water-gage,the Valve F, bearing upon the end of the tube G, the valve H,

connected to the said valve F, and the tube G, adjustable in the casingB, and having an outer seat for the valve F and an inner seat for thevalve II, all substantially as specied.

3. The combination of the tubular valve F,

. Substantially as specified.

In testimony whereof I have signed my name Io to this specification inthe presence of two subscribing witnesses.

JAMES MCCAFFREY.

Witn esses WILLIAM F. DAVIS, HARRY SMITH.

